Family history has been considered a risk factor for permanent
congenital, delayed onset, or progressive hearing loss by the Joint
Committee on Infant Hearing since 1973 [1-6].They found that, of 36 children with a positive
family history, 26 had bilateral severe to profound loss, 3 had
bilateral mild to moderate loss, and 4 had unilateral severe to
profound losses.Zamani et al. [11] conducted a cross-sectional investigation of
infants who were referred for diagnostic assessment to Tehran
University of Medical Sciences children's hospitals between
September 2000 and February 2002.Various researchers have noted a lack of efficiency in targeted
hearing surveillance programs in Australia and have recommended that comprehensive research be conducted to assess
specific risk factors [16,21].Specifically, it aimed
to investigate:
 The prevalence and yield of family history as a reported risk
factor in children with congenital and postnatal hearing loss,
 The audiometric characteristics of hearing loss in children with a
positive family history,
 The nature of the familial relationships between family members
with pediatric hearing loss.As noted by Cone-Wesson et al. [8] in their comparative
report of data from normally-hearing neonates with data from
hearing-impaired neonates, many subjects had more than one risk factor for pediatric hearing loss.Billings and Kenna [20] isolated each risk factor and assessed
the severity and laterality (unilateral or bilateral) of the hearing
loss identified.They found that, of 38 children whose hearing
losses were likely to be of genetic origin, 23 had thresholds >70 dB
HL and 15 had thresholds 70 dB HL. However, these authors did
not note whether these losses were bilateral or unilateral and it
should also be considered that'genetic' does not necessarily equate
with parental report of a positive family history.It is essential that the aforementioned gaps in the current
literature are addressed to determine the validity of family history
as a risk factor for both congenital and postnatal hearing loss.In fact,the true validity has been often obscured, as studies have
failed to isolate family history from additional confounding risk
factors.Halpern and colleagues [12] also failed to find a relationship
between family history and congenital hearing loss, although this may have been influenced by the study population, which
consisted only of babies admitted to neonatal intensive care units.Evidence of the nature of familial relationships implicated in both congenital and postnatal
hearing loss may be useful in forming more specific case-history
questions for use in screening processes and may guide screening
programs to identify children at a higher risk of hearing loss due
to such nature.Another study by Weichbold et al. [17] also aimed to assess the
relationship between various risk factors and postnatal hearing
loss.Hence, various studies
have attempted to provide information on the audiometric
characteristics of children with risk factors for pediatric hearing
loss.Beswick et al. [15] reported on familial relationships in
postnatal hearing loss but only included the child's parents and
siblings.Differing definitions of positive family history along
with varied methods of obtaining a child's history will lead to
different prevalence estimates.Sutton and
Rowe [9] calculated a similar prevalence of family history in infants
with congenital hearing loss of 26.2%.Yet, again, both
of the latter authors remarked that family history was not
examined as a sole risk factor.Studies by Kountakis et al. [13,14] have also concluded that family
history was not a significant risk factor.A recent study using data from Queensland
Health's Healthy Hearing Targeted Surveillance Program found a
statistically significant correlation between family history and
postnatal hearing loss [15].Therefore, other studies have investigated the relationship
in postnatal cohorts.